Quinine Sulphate Microparticles as Treatment for Leishmaniasis.

Background. Leishmaniasis is a neglected tropical disease caused by the Leishmania parasite and transmitted by the female phlebotomine sandfly. The disease can affect the skin (least fatal) or internal organs (most fatal). Current treatment options for leishmaniasis have a number of adverse effects, and there appears to be resistance by the protozoan parasite (Leishmania spp.). Reports suggest that quinine sulphate, not indicated for leishmaniasis, is effective in killing the Leishmania parasite. Indeed, the efficacy of any drug is dependent on the concentration at the target site, which is also almost dependent on drug formulation. The current study assessed the pharmacokinetic profile of the microparticulate formulation of quinine sulphate and its in vitro and in vivo efficacy against Leishmania donovani. Methods. Quinine sulphate was encapsulated in bovine serum albumin by the spray-drying method. Quinine sulphate microparticles were evaluated for size, zeta potential, drug content, encapsulation efficiency, and in vitro release properties. Afterwards, the pharmacokinetic characteristics of quinine sulphate microparticles were estimated and in vivo efficacy studies were also conducted. Results. The size range of the quinine sulphate microparticles was between 2.0 and 5.0 µm. Microparticles had an average zeta potential of −35.2 mV and an encapsulation efficiency of 94.5%. Also, Cmax, t1/2, and AUC were all significantly desirable for quinine sulphate microparticles compared to the drug powder. Quinine sulphate microparticles significantly reduced parasite load in rat organs than amphotericin B. Conclusion. Overall, quinine sulphate microparticles had better pharmacokinetic profile and showed higher efficacy against Leishmania donovani parasites in vivo. Thus, quinine sulphate microparticles have the potential, especially, in treating visceral leishmaniasis.